I have a mule pro with power steering and love it, my wife easily drives it and likes it as well. The shorter turning radius compared to the other 2 row UTV's on the market was a big factor for me, we live in the pineywoods and it's fairly tight getting around some of the trails. I like the nimble yet comfortable feel of the Mule's ride over the Cadillac-like ride of the Can Am, I haven't ridden a new Ranger so I can't speak to the ride of them.
This could probably be said here or on the thread about the UTV accident, but folks should really think about what they're doing with a UTV before they buy it or start modifying it with lifts, metal roofs, high seats, etc. Practically anything you do to these machines raises the center of gravity and makes them top heavy, I've ridden some that are modified to the point of being dangerous with any sudden turn above walking speed. Personally for what we do with our Mule, I haven't found any limitations to the factory suspension setup, but I also don't push the limits like I used to. These aren't the small 4 wheelers or dirt bikes we grew up with, I keep a Raptor 660 around for the fun stuff.